Connectors made of resin have conventionally been used to connect fuel pipes of an automobile to each other. The undermentioned patent document 1 discloses an example of the connectors. The connector disclosed in the document includes a housing for connecting ends of two pipes to be connected, a retainer which retains one of the pipes inserted through the housing and a checker for detecting the one pipe inserted thereby to assume a normal position.
When the pipe is inserted into the housing to assume the normal position, in patent document 1, the retainer is moved to a lock position by pushing the checker thereby to retain the pipe in a locked state. Furthermore, when the retainer turns to a locking state, the checker is allowed to be detached from the retainer, whereby the worker can confirm completion of pipe connection.